This disclosure relates to a strategy for controlling operating margin of a compressor section of a gas turbine engine.
A compressor section of a gas turbine engine is typically operated with regard to a designed operating line over a range of compressor pressure ratios and mass airflows. The engine is normally operated in a regime such that there is an operating margin between the designed operating line and a maximum operating line beyond which operation of the compressor section may become unstable with regard to stall, surge or flutter.
Typically, the designed operating line is set according to predefined parameters that are input into a schedule that is used to control operation of the compressor section. For instance, the compressor section may include variable vanes that are movable subject to the schedule such that the operating margin is maintained across the operating regime of the aircraft. A challenge, however, in setting the schedule is that the predefined parameters are set according to the most extreme operating conditions that the engine is expected to experience. Often compressor designers must sacrifice engine fuel economy or component life to ensure safe operation under all these conditions.